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. 2005 Jan;16(1):128–140. doi: 10.1091/mbc.E04-10-0892

Figure 8.

Figure 8.

Targeting of synaptic vesicle proteins to small vesicles in Ap3b1-/- and Ap3b2-/- brains. High-speed supernatants (S2) from control, Ap3b1-/-, and Ap3b2-/- brain homogenates were fractionated in 5–25% glycerol gradients to resolve small vesicles (peak at fractions 7–9). Synaptic vesicle protein levels across gradients were determined by immunoblot by using antibodies against: ZnT3 (A), ClC-3 (B), synaptophysin (Sphysin, C), SV2 (D), and vacuolar ATPase (vATPase, E). Only ZnT3 and ClC-3 sedimentation pattern and their protein levels are altered in Ap3b1-/- and Ap3b2-/- brain vesicles. (F–J) Normalized protein distribution of ZnT3 (n = 5), ClC-3 (n = 4), and Sphysin (n = 3), SV 2 (n = 2), and vATPase (n = 2): Each fraction value is a figure normalized to the total amount of control samples. Closed circles represent control vesicles, and open squares and circles correspond to Ap3b1-/- and Ap3b2-/- vesicles, respectively. ZnT3 (F) increases in the absence of ubiquitous AP-3, and decreases in absence of neuronal AP-3. Total protein level of ClC-3 (G) increases in both Ap3b1-/- and Ap3b2-/- S2. The increased ClC-3 in Ap3b1-/- S2 still has the same distribution shape as control S2, whereas the increased ClC-3 in Ap3b2-/- is redistributed to membranes bigger than synaptic vesicles. Note the peak of open circle is shifted toward left. Fraction 1 corresponds to the bottom in all gradients (A–E).